plate out verb 2plate-out noun 1forms 3 verb2 •To be neutralized and deposited onto a solid surface.In this galvanic cell, Ag⁺ ions are reduced into metallic silver and plate out onto an electrode. •To cause to plate out.Electrolysis or electrochemical deposition may be used either to plate out the active material of interest or to plate out other substances leaving the active material in solution. — 2009 plate-out noun1 •That which has plated out; dissolved metal deposited onto a solid surface. formsplated out · plating out · plates out